Patent document 1 discloses a hydraulic braking system including: (i) a cylinder device including (a) a housing, (b) a pressurizing piston fluid-tightly and slidably fitted in the housing, (c) a front pressure chamber provided in front of the pressurizing piston, and (d) a rear chamber provided at a rear of the pressurizing piston; and (ii) a brake cylinder, coupled to the front pressure chamber, for a hydraulic brake for restraining rotation of a wheel.
When the pressurizing piston is located at its back end position in this cylinder device, the front pressure chamber communicates with the reservoir. Brake fluid is supplied to the rear chamber to advance the pressurizing piston, causing the front pressure chamber to be disconnected from the reservoir to produce hydraulic pressure. This hydraulic pressure is supplied to the brake cylinder to activate the hydraulic brake.